# Copyright The Lightning team.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
import warnings
from functools import partial, wraps
from typing import Any, Callable

from torchmetrics import _logger as log


def rank_zero_only(fn: Callable) -> Callable:
    """Call a function only on rank 0 in distributed settings.

    Meant to be used as an decorator.

    """

    @wraps(fn)
    def wrapped_fn(*args: Any, **kwargs: Any) -> Any:
        if rank_zero_only.rank == 0:
            return fn(*args, **kwargs)
        return None

    return wrapped_fn


# add the attribute to the function but don't overwrite in case Trainer has already set it
rank_zero_only.rank = getattr(rank_zero_only, "rank", int(os.environ.get("LOCAL_RANK", 0)))


def _warn(*args: Any, **kwargs: Any) -> None:
    warnings.warn(*args, **kwargs)


def _info(*args: Any, **kwargs: Any) -> None:
    log.info(*args, **kwargs)


def _debug(*args: Any, **kwargs: Any) -> None:
    log.debug(*args, **kwargs)


rank_zero_debug = rank_zero_only(_debug)
rank_zero_info = rank_zero_only(_info)
rank_zero_warn = rank_zero_only(_warn)
_future_warning = partial(warnings.warn, category=FutureWarning)


def _deprecated_root_import_class(name: str, domain: str) -> None:
    """Warn user that he is importing class from location it has been deprecated."""
    _future_warning(
        f"Importing `{name}` from `torchmetrics` was deprecated and will be removed in 2.0."
        f" Import `{name}` from `torchmetrics.{domain}` instead."
    )


def _deprecated_root_import_func(name: str, domain: str) -> None:
    """Warn user that he is importing function from location it has been deprecated."""
    _future_warning(
        f"Importing `{name}` from `torchmetrics.functional` was deprecated and will be removed in 2.0."
        f" Import `{name}` from `torchmetrics.{domain}` instead."
    )